Endovascular treatment of dural arteriovenous fistula after cerebral venous thrombosis in a child

Case report: An 8-year-old male presented with sudden severe headache, and normal neurological examination. CT scan showed brain edema mainly in posterior temporal fossae, while MR had signs of chronic sinovenous thrombosis (CSVT) affecting superior sagittal, right transverse and bilateral sigmoid sinuses. He was medicated with anticoagulant, but after 3 months he presented new and more serious symptoms: worse headache associated with tinnitus, episodes of mental confusion and, finally, lowering of the level of consciousness. MR angiography showed numerous ectasic cortical veins in temporal lobes and posterior fossa and a venous aneurysm in the right perimesencephalic cistern, suggesting multiple dural arteriovenous fistula (DAVF). Digital subtraction angiography confirmed complex DAVF with afferents from left vertebral, internal and external carotid arteries, draining mainly through a stenotic left sigmoid sinus and causing reflux to cortical veins and transverse sinus, Cognard grade IV. Endovascular treatment was performed in three sessions under general anesthesia and full intravenous heparinization. Left external carotid artery branches (occipital, posterior auricular, middle meningeal, ascending pharyngeal arteries) and vertebral artery branch (posterior meningeal artery) were occluded with Onyx, decreasing arteriovenous flow (fig.2B). A stent was opened from left sigmoid sinus to jugular fossa and percutaneous angioplasty performed with balloons. The child’s symptoms improved completely shortly after treatment without recurrence in 4-years of image follow-up.

Discussion: CSVT is a rare condition affecting 0.56–0.67 per 100,000 children per year, with high mortality and long-term neurological deficits. Despite controversial etiology regarding congenital factors, authors tend to agree with development of DAVF in response to venous sinus hypertension caused by CSVT. The CSVT can regress spontaneously or develop DAVF. Anticoagulation with heparin is the gold standard treatment, however the response in our case was not satisfactory. Anticoagulation has capacity to avoid thrombus propagation, allowing sinus recanalization. The main indication for endovascular approach is clinical deterioration despite anticoagulation.

Final Considerations: Similar as in adult population, DAVF is highly associated with CSVT in children. In cases of clinical deterioration scenario, endovascular treatment is a safe and feasible option.